# Effect of reactive gyroscopic couple on an aeroplane, whenit takes left turn and the rotation of propeller is in clockwise

What is the effect of reactive gyroscopic couple on an aeroplane, when the aeroplane is taking left turn and the rotation of propeller is in clockwise when seen from back side of the aeroplane?
Options:

a. rise of the nose and fall of the tail of aeroplane
b. fall of the nose and rise of the tail of aeroplane
c. sometimes a. and sometimes b.
d. no effect

Correct Answer: a. rise of the nose and fall of the tail of aeroplane

Explanation:

Gyroscope is a device which is used for measuring and maintaining orientation. The principles of angular momentum is used for this purpose. While an aeroplane is taking left turn as shown in figure and the propeller is rotating in clockwise direction when seen from back side of the plane. As the propeller is rotating in ox axis, the axis ox is called as axis of spin. The plane is taking right turn that means axis ox is rotating towards the axis oz.

We can find direction of gyroscopic couple by the right hand rule. According to the gyroscopic effect, if we cover axis of spin (ox in this case) with right hand as the curved fingers indicate the direction of rotating propeller and rotate that axis in the direction of the aeroplane is taking turn, then the curved fingers show the direction of active gyroscopic couple and the direction of reactive gyroscopic couple is exactly opposite but equal in magnitude as shown in figure. Thus it results in rising of the nose and falling of the tail of aeroplane.
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#### Discussion

• RE: Effect of reactive gyroscopic couple on an aeroplane, whenit takes left turn and the rotation of propeller is in clockwise -Saravanan (10/28/17)
• Sir, why can't we take the active gyroscopic couple into account,in the case of finding the force on the plane
• RE: Effect of reactive gyroscopic couple on an aeroplane, whenit takes left turn and the rotation of propeller is in clockwise -suraj kumar mishra (10/18/16)
• Sir,why only the effect of reactive gyroscopic couple is considered?
The active gyroscopic couple should should counterbalance the effect of reactive gyroscopic couple.but this is not happening.why?
• RE: Effect of reactive gyroscopic couple on an aeroplane, whenit takes left turn and the rotation of propeller is in clockwise -ms manoj (10/01/16)
• really thanks to you guys....it was really really helpful in giving me a clear view on this topic.........
• RE: Effect of reactive gyroscopic couple on an aeroplane, whenit takes left turn and the rotation of propeller is in clockwise -SA H Il (04/10/16)
• Very informative blog with so easy language.